1. Technical Field
The present invention relates to a method for forming an oriented film, an oriented film, a substrate for an electronic device, a liquid crystal panel, and an electronic device.
2. Background Art
Projection display devices for projecting images on a screen are known. Liquid crystal panels have been mainly used for forming images in such projection display devices.
Such liquid crystal panels usually have an oriented film set so that a prescribed pretilt angle is demonstrated in order to orient liquid crystal molecules in a fixed direction. A method for the manufacture of such oriented films is known by which a thin film composed of a polymer compound such as a polyimide, which was formed on a substrate, is unidirectionally rubbed with a cloth such as rayon (for example, see JP-A-H10-161133 (Claims)).
However, the oriented films composed of polymer compounds such as polyimides sometimes demonstrate light-induced deterioration under certain working environments and durations of use. If such light-induced deterioration occurs, materials constituting the oriented film, liquid crystal layer, and the like can decompose and the decomposition products can produce an adverse effect on the performance of liquid crystals.
Another problem is that the rubbing treatment produces electrostatic charges and dust, thereby decreasing reliability.
It is an object of the present invention to provide an oriented film that has excellent light resistance and allows for a more reliable control of a pretilt angle, to provide a substrate for an electronic device, a liquid crystal panel, and an electronic device comprising such an oriented film, and to provide a method for forming such an oriented film.